Homework 1

DATA 202 - Alexander - Spring 2024

Please submit Homework 1 responses as a .pdf file on Canvas here.

Exercise 1.1

The USPHS Syphilis Study at Tuskegee was one of many historical cases of scientific racism and unethical practices enacted by the U.S. government. Was the USPHS Syphilis Study at Tuskegee an experimental or observational study? Explain your reasoning.

Exercise 1.2

Conduct a web search and literature review to identify two (2) other cases where data and/or information was collected using unethical practices. Provide a brief explanation of each case and its significance to understanding ethics. Include a full citation of all sources.

Exercise 1.3

There are many definitions of statistics. What is the definition of statistics that has been used in our course lectures? Conduct a web search and find two (2) alternative definitions of statistics. Include a full citation of all sources.

Exercise 1.4

Based on your current understanding of statistics, what should it mean to be critical in the context of statistics? Explain your thinking. Include a full citation of all sources.

Exercise 1.5

You have been tasked with identifying data for a new study on homelessness and housing insecurity in your local area. Identify and describe two (2) of each variable type that could be collected for this study: nominal, ordinal, discrete, continuous. That is, identify and fully describe two nominal, two ordinal, two discrete, and two continuous variables that could be used to gather insights about homelessness and housing insecurity. Your descriptions should be detailed.

Exercise 1.6

Your local city council plans to conduct a 2024 census of the local homeless population. You have been hired as a data analyst to identify priorities for the project. This census is part of a broader effort to understand the issues experienced during homelessness and to find ways to mitigate issues given the recent increase in the homeless population. What are some potential ethical issues that could arise with the councils’ plans to conduct a local homeless census? In the city’s plan to collect data on those experiencing homelessness, should informed consent be obtained per the IRB? If so, why and how?

Exercise 1.7

Describe the contents of the data set below and what the values most likely represent.

# A tibble: 6 × 62
  country  year_1960 year_1961 year_1962 year_1963 year_1964 year_1965 year_1966
  <chr>        <dbl>     <dbl>     <dbl>     <dbl>     <dbl>     <dbl>     <dbl>
1 Afghani…   8996967   9169406   9351442   9543200   9744772   9956318  10174840
2 Albania    1608800   1659800   1711319   1762621   1814135   1864791   1914573
3 Algeria   11057864  11336336  11619828  11912800  12221675  12550880  12902626
4 America…     20127     20605     21246     22029     22850     23675     24473
5 Andorra      13410     14378     15379     16407     17466     18542     19646
6 Angola     5454938   5531451   5608499   5679409   5734995   5770573   5781305
# ℹ 54 more variables: year_1967 <dbl>, year_1968 <dbl>, year_1969 <dbl>,
#   year_1970 <dbl>, year_1971 <dbl>, year_1972 <dbl>, year_1973 <dbl>,
#   year_1974 <dbl>, year_1975 <dbl>, year_1976 <dbl>, year_1977 <dbl>,
#   year_1978 <dbl>, year_1979 <dbl>, year_1980 <dbl>, year_1981 <dbl>,
#   year_1982 <dbl>, year_1983 <dbl>, year_1984 <dbl>, year_1985 <dbl>,
#   year_1986 <dbl>, year_1987 <dbl>, year_1988 <dbl>, year_1989 <dbl>,
#   year_1990 <dbl>, year_1991 <dbl>, year_1992 <dbl>, year_1993 <dbl>, …

# A tibble: 6 × 62
  country  year_1960 year_1961 year_1962 year_1963 year_1964 year_1965 year_1966
  <chr>        <dbl>     <dbl>     <dbl>     <dbl>     <dbl>     <dbl>     <dbl>
1 Vietnam   32670048  33666111  34683410  35721213  36780001  37858947  38958046
2 Virgin …     32500     34300     35000     39800     40800     43500     46200
3 West Ba…        NA        NA        NA        NA        NA        NA        NA
4 Yemen, …   5315351   5393034   5473671   5556767   5641598   5727745   5816241
5 Zambia     3070780   3164330   3260645   3360099   3463211   3570466   3681953
6 Zimbabwe   3776679   3905038   4039209   4178726   4322854   4471178   4623340
# ℹ 54 more variables: year_1967 <dbl>, year_1968 <dbl>, year_1969 <dbl>,
#   year_1970 <dbl>, year_1971 <dbl>, year_1972 <dbl>, year_1973 <dbl>,
#   year_1974 <dbl>, year_1975 <dbl>, year_1976 <dbl>, year_1977 <dbl>,
#   year_1978 <dbl>, year_1979 <dbl>, year_1980 <dbl>, year_1981 <dbl>,
#   year_1982 <dbl>, year_1983 <dbl>, year_1984 <dbl>, year_1985 <dbl>,
#   year_1986 <dbl>, year_1987 <dbl>, year_1988 <dbl>, year_1989 <dbl>,
#   year_1990 <dbl>, year_1991 <dbl>, year_1992 <dbl>, year_1993 <dbl>, …

Exercise 1.8

sum(1:51)

What is the meaning of the code chunk sum(1:51)?
What is the numerical output?

Exercise 1.9

The population of five countries is listed in a data set using computational scientific notation.

Numerically expand the population for each country.

Country 1: 2.06139E8
Country 2: 8.9561E7
Country 3: 2.77E7
Country 4: 2.72815E5
Country 5: 6.077E3

Exercise 1.10

Describe the error in the following attempt to construct a data frame.

vec1 <- c(1, 2, 3, 4)
vec2 <- c("a","b","c","d")
vec3 <- data.frame(T, F, F, T)
df <- data.frame(vec1, vec2, vec3)